In a medium bowl, mix the rice flour with the poppy seeds, 1/2 teaspoon salt and the pepper. Whisk in the club soda and cold water. Let the batter rest for 20 minutes.

Heat 1/2 inch of oil in a small skillet just until shimmering. Holding each sage leaf by the stem, dip it into the batter to coat both sides. Add to the oil and fry over moderately high heat until lightly golden, about 30 seconds. Drain on paper towels and sprinkle lightly with salt. Serve warm or at room temperature.